Efforts to stimulate lymphocytes from measles seropositive and two patients with subacute sclerosing panencephalitis (SSPE) with either commercially available measles virus or virus isolated from a known case of SSPE failed to show any significant data using a microculture assay. Similar results were obtained using lymphocytes from two patients with active cytomegalovirus (CMV) infections and CMV seropositive individuals using CMV suspensions.
On the other hand, lymphocytes from the patients with subacute sclerosing panencephalitis exhibited in vitro blastogenesis in culture with SSPE virus-infected HeLa cells. Similarly, lymphocytes from the CMV-infected patients demonstrated blastogenesis when cocultivated with CMV-infected WI-38 cells. This affords a new method for determining the cell-mediated immune capacity of patients with "slow" virus diseases.